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Michouxdinium
From Williams et al., 2017:
[Michouxdinium, Williams et al., 2015, p. 306–307.
Type species: Kisselevia aculeata, Michoux, 1988 (pl.1, figs.1,4,7; text-fig.5A–B)]
Stratigraphic occurrence: Latest Early Eocene to Early Oligocene (Ypresian Rupelian).
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Original description [Williams et al., 2015]:
Diagnosis:
Wetzelielloidean cysts with a soleiform archeopyle and processes that are distally trabeculate.
Description:
Shape: Dorso-ventral outline of pericyst rhomboidal, horns distinct but of limited development. Dorso-ventral outline of endocyst rhomboidal. Wall structure: Periphragm thin, ornamented with penitabular processes or clusters of intratabular processes which are distally connected by trabecula; process tips may be distally aculeate. Endophragm thin, smooth to granular.
Pericoels: Cornucavate to narrowly circumcavate.
Tabulation: Partially to completely delineated by trabecular network which is supported by penitabular processes and forms simulate complexes. Archeopyle: Soleiform. Endoarcheopyle of similar size to periarcheopyle.
Furrows: Delineated by processes and trabecula.
Size: Large.
Discussion/Affinities:
Other genera with a soleiform archeopyle are Castellodinium, Rhombodinium, Talladinium and Wetzeliella. Castellodinium has sutural to penitabular processes. Rhombodinium has a pericyst that is smooth or is ornamented only with features of low relief. Species of Talladinium have processes that are distally united by an ectophragm. Wetzeliella has processes that are distally free. Kledodinium, Sagenodinium and Sophismatia also have trabeculate processes, but Kledodinium has a latiepeliform archeopyle, Sagenodinium has a hyperepeliform archeopyle and Sophismatia has an equiepeliform archeopyle. The holotype of Michouxdinium aculeatum has a pericyst length of 124 µm and width of 121 µm. Bujak in Bujak et al. (1980) recorded the following range of dimensions for his specimens of Michouxdinium variabile: overall pericyst length 80-117 µm, overall pericyst width 82-124 µm; overall endocyst length 65-92 µm, overall endocyst width 66-100 µm.
[Michouxdinium, Williams et al., 2015, p. 306–307.
Type species: Kisselevia aculeata, Michoux, 1988 (pl.1, figs.1,4,7; text-fig.5A–B)]
Stratigraphic occurrence: Latest Early Eocene to Early Oligocene (Ypresian Rupelian).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description [Williams et al., 2015]:
Diagnosis:
Wetzelielloidean cysts with a soleiform archeopyle and processes that are distally trabeculate.
Description:
Shape: Dorso-ventral outline of pericyst rhomboidal, horns distinct but of limited development. Dorso-ventral outline of endocyst rhomboidal. Wall structure: Periphragm thin, ornamented with penitabular processes or clusters of intratabular processes which are distally connected by trabecula; process tips may be distally aculeate. Endophragm thin, smooth to granular.
Pericoels: Cornucavate to narrowly circumcavate.
Tabulation: Partially to completely delineated by trabecular network which is supported by penitabular processes and forms simulate complexes. Archeopyle: Soleiform. Endoarcheopyle of similar size to periarcheopyle.
Furrows: Delineated by processes and trabecula.
Size: Large.
Discussion/Affinities:
Other genera with a soleiform archeopyle are Castellodinium, Rhombodinium, Talladinium and Wetzeliella. Castellodinium has sutural to penitabular processes. Rhombodinium has a pericyst that is smooth or is ornamented only with features of low relief. Species of Talladinium have processes that are distally united by an ectophragm. Wetzeliella has processes that are distally free. Kledodinium, Sagenodinium and Sophismatia also have trabeculate processes, but Kledodinium has a latiepeliform archeopyle, Sagenodinium has a hyperepeliform archeopyle and Sophismatia has an equiepeliform archeopyle. The holotype of Michouxdinium aculeatum has a pericyst length of 124 µm and width of 121 µm. Bujak in Bujak et al. (1980) recorded the following range of dimensions for his specimens of Michouxdinium variabile: overall pericyst length 80-117 µm, overall pericyst width 82-124 µm; overall endocyst length 65-92 µm, overall endocyst width 66-100 µm.